'Annihilation’ review: Natalie Portman steps up in sci-fi hodgepodge

In the latest show of big-screen girl power, Oscar winner Natalie Portman rocks a machine gun and microscope with equal authority while tracking an alien force in "Annihilation."

Moviegoers, meanwhile, may wish they had machetes to hack through this trippy but confusing and ultimately less than fully satisfying sci-fi hodgepodge written and directed by Alex Garland, based on Jeff VanderMeer's "Southern Reach" trilogy.

The story begins as a beam or missile or something alien strikes a lighthouse. An iridescent field arises that surrounds the area in what looks like supersized soap bubbles. Scientists call the phenomenon "the Shimmer." Nothing that enters the area — drones, search animals, people — comes back. Except Kane (Oscar Isaac), a soldier. But he's changed — and is in dire shape.

To save him, his wife Lena (Portman), whose microbiology background may illuminate what's going on at the lighthouse, volunteers to enter the dangerous domain with an all-female group. The mission: Trek to ground zero and get to the bottom of things. (So you'd think that one of them would have a head lamp for navigating at night.)

The band of sisters includes Ventress (Jennifer Jason Leigh, locked in mope mode), a psychologist, scientists Radek (Tessa Thompson) and Sheppard (Tuva Novotny) and paramedic Thorensen (Gina Rodriguez). Each supporting character gets one key trait, since it's just a matter of time before Lena is left to be the one to step up.

She does, of course, and so does gritty-vulnerable Portman who holds her own and convinces even amid some inexplicable and silly looking events. Like a belched-up light show.

Garland, whose previous film, "Ex Machina," boasted a streamlined elegance, delivers some eye-popping visuals in the new film. The expedition encounters funky flowers, hybrid beasts and other strange and scary genetic mutations of flora, fauna and people. There are a couple adrenaline-pumping frights and one gross-out, blood-and-guts moment.

Mostly there are questions about what "Annihilation" wants to say. Is it about an alien takeover? Self-destruction on a daily basis — and at a cellular level? Identity and what we see in the mirror? The perils of infidelity? All the above? None of the above? Your mileage may vary — along with patience.